It a first object of the invention to provide an improved trailer which allows movement of the trailer from a raised transport position to a lowered loading/unloading position in which the frame of the trailer is moved to be at or adjacent to the ground and particularly to provide a trailer including a fender which accommodates movement of the wheel during lowering of the trailer.

According to a first aspect of the invention there is provided a trailer comprising: a trailer frame having at least two longitudinal beams parallel to a direction of movement of the trailer; a hitch at a forward end of the frame for attachment to a towing vehicle; at least two ground wheels for supporting the frame for movement across the ground; and at least two mounting assemblies each associated with a respective ground wheel for attaching the ground wheel to the frame; each mounting assembly comprising: a first member connected to the frame for movement therewith; and a second member having the wheel mounted thereon for rotation about a wheel axis; the second member being movably mounted on the first member so as to move the wheel axis from a first raised position in which the frame is lowered to a position at or adjacent the ground to a second operating position lower than the first position in which the frame is raised for transport.

According to a second aspect of the invention there is provided a trailer comprising: a trailer frame having at least two longitudinal beams parallel to a direction of movement of the trailer; a hitch at the forward end of the trailer for attachment to a to a towing vehicle; at least two ground wheels for supporting the frame for movement across the ground; and at least two mounting assemblies each associated with a respective ground wheel for attaching the ground wheel to the frame; wherein the frame comprises; a first frame portion having a first and second beam portion; a second frame portion having a first and a second beam portion; each of the first and second beam portions of the first frame portion comprising a hollow tube with an open end; each of the first and scanned beam portions of the second frame portion extending into the open end of a respective one of the first and second beam portions of the first frame portion; and means for allowing sliding movement of the first and second beam portions of the second frame portion relative to the first frame portion for adjusting the length of the frame.

According to a third aspect of the invention there is provided a trailer comprising; a trailer frame having at least two longitudinal beams parallel to a direction of movement of the trailer; a hitch at a forward end of the frame for attachment to a towing vehicle; at least two ground wheels for supporting the frame for movement across the ground; and at least two mounting assemblies each associated with a respective ground wheel for attaching the ground wheel to the frame; each mounting assembly comprising: a first member connected to the frame for movement therewith; a second member having the wheel mounted thereon for rotation about a wheel axis, the second member being movably mounted on the first member so as to move the wheel axis from a first raised position in which the frame is lowered to a position at or adjacent the ground to a second operating position lower than the first position in which the frame is raised for transport; and a fender mounted on the trailer frame for covering the wheel during transport, the fender including at least a portion thereof which is movable relative to the wheel to accommodate the movement of the wheel to the raised position.

One embodiment of the invention will now be described in conjunction with the accompanying drawings in which: Figure 1 is a top plan view of the trailer according to the present invention with one side portion of the frame and the associated wheel thereon omitted for convenience of illustration.

Figure 2 is a top plan view of a center portion only of the frame of figure 1 showing the frame in an extended position.

Figure 3 is a side elevational view of the frame portion of Figure 2.

Figure 4 is a cross sectional view along the lines 4-4 of Figure 2.

Figure 5 is a top plan view, partly broken away, of the side portion only of the frame of Figure 1 on an enlarged scale showing particularly the wheel mounting assembly.

Figure 6 is view along the lines 6-6 of Figure 5.

Figure 7 is a view along the line 7-7 of Figure 5 showing the wheel mounting assembly in the first raised position of the wheel axis.

Figure 8 is a view similar of Figure 7 showing the mounting assembly in the second lowered position of the wheel axis.

Figure 9 is a top plan view of a wheel of the trailer of the above figures showing a fender for the wheel which is arranged to accommodate the lifting movement of the wheel.

Figure 10 is a front elevational view of the wheel and fender of Figure 9 showing the fender in a raised position.

Figure 11 is a front elevational view of one part only of the fender of Figures 9 and 10 showing the fender in the normal locked operating position.

Figure 12 is a front elevational view of a modified arrangement of fender.

The frame of the embodiment comprises a first frame portion 10 and a second frame portion 11 which can be adjusted from an inwardly closed shorter position shown in figure 1 to an extended position shown in Figure 2.

The first frame portion 10 comprises a first beam 12 and a second beam 13 which are parallel and parallel to a direction of longitudinal movement of the trailer as indicated at 14. The beams 12 and 13 are indicated by a first transverse beam 15 and a second rear transverse beam 17. At the front of the beams 12 and 13 is provided a pair of inwardly incline beam portions 18 and 19 which converge to central apex at which is provided a hitch pole 20 extending forwardly from the frame for attachment to a towing vehicle.

The rear or second frame portion comprises a first beam 21 and a second beam 22. Each of first and second beams 21,22 is formed of a first tubular portion 23 of the same dimensions as a tubular portion forming the beam 12,13 and a second tubular portion of reduced dimensions for sliding inside of the tubular portion defining the beam 12,13. Thus in the retracted position shown in Figure 1, the end 24 of the portion 23 lies substantially immediately adjacent the end 25 of the beam 12. The beam 13 and the corresponding beam 22 of the second portion of the same construction.

At the forward end of the smaller beam portion of the rear frame is provided a pair of guide rollers 25,26 which roll on the inside surfaces of the top and bottom wall of the beam 12,13 as best shown in figure 3.

At the rear end of the beams 12 and 13 is provided a pair of rollers 27,28 which roll on the outside surface of the smaller portion of the beams 21,22. Thus the smaller portions of the beam 21 and 22 are guided by the pair of roller as best shown in Figure 3 for sliding movement longitudinally of the beams 12,13.

The longitudinal sliding movement of the rear portion 11 or of the front portion 12 is then effected by a cylinder schematically indicated at 29 which is connected between a coupling 30 at the rear end of the hitch pole 20 and a coupling 31 on the rear frame portion 11.

The rear frame 11 further includes a third beam 32 parallel to and coplanar with the beams 21 and 22. The three beams are indicated by a transverse rear beam 33 defining a rear part of the frame with the rear beam extending outwardly beyond the beams 21 and 22 to form projecting portions 33A and 33B. The third beam 32 rides on a roller 35 carried on a rear upper part of the transverse beam 17. Forwardly the roller 35, the beam 32 splits into two transverse members 36 and 37 which diverge outwardly in a Y-shape toward the beams 12 and 13. Adjacent the forward end of each of the transverse members is provided a horizontal shaft 38 each of which carries a roller 39 running within a channel guide track 40 mounted on an inwardly facing surface of the respective beam 12,13. Thus the forward end of the third beam is guided by the tracks 40 and is supported against vertical movement relative to the front frame portion 10. The coupling 31 is located at the apex between the legs of the Y-shape.

In this way the length of the frame can be adjusted from the position shown in Figure 1 which is the short position to the extend position shown in figure 2.

During this movement the position of the beams of the frame are maintained in forward position so that the frame remains coplanar and is structural sound. In the retracted position shown in Figure 2, the pointed end of each of the transverse member 36,37 engages into a triangular receptacle 41 carried on the inwardly facing surface of the beam 12,13. The central frame section defined by the front portion 10 and the rear portion 11 is supplemented by a pair of side frame portion generally indicated at 45. The right hand frame as shown in Figure 1 but the left hand frame is omitted for convenience of illustration. Each frame portion comprises a horizontal beam 46 which is supported on the respective beam 12,13 by a pair of inclined support struts 47,47A. Each of the struts 47,47A is attached to a plate 48 at its inner end bolted to the outside surface of the beam 12. Thus the beam 46 is supported at a height raise from the horizontal plane of the main frame. The beam 46 is however rigidly attached to the main frame and remains in fixed position relative to thereto.

The frame thus constructed by a pair of wheel assemblies generally indicated at 50. Again the right hand wheel assembly is shown in Figure 1 and the left hand wheel assembly is omitted for convenience of illustration. It will be appreciated that the frame portion 45 and the wheel 50 of the right is symmetrical relative to the same elements on the left hand side.

The wheel assembly 50 comprises a ground wheel 51, a wheel mounting assembly 52, a pivot arm 53 and a leaf spring 54.

The pivot arm 53 is pivotally connected by a bracket 55 attached to the beam 1 by a plate 56 intermediate the plate 48. The arm 53 can thus pivot upwardly and downwardly in a suspension movement of the wheel against the bias of the spring 54 attached to the beam 46 by couplings 54A.

Other types suspension can be used depending upon requirements and the present invention is not limited to the particular type of suspension shown and described herein.

The arm 53 projects beyond its connection to the base of the leaf spring 54 and thus provides a support for the wheel mounting 52. The wheel mounting 52 comprised a first member 60 in the form of a substantially vertical plate welded to an outer end 61 of the arm 53 and standing upwardly therefrom so the arm is attached to the bottom of the plate 60. The plate carries a spindle 62 projecting forwardly from the plate at a position directly above the arm and extending horizontal from the plate when the plate stands vertical. The angle of the plate varies during suspension movement.

The mounting assembly 52 further includes a hub 63 forming a second member of the mounting assembly which is movable relative to the first member. The hub 63 includes a central ring 64 mounted on the spindle 62 for rotation about a rotation axis 65 defined by the spindle 62. The hub 63 carries a spindle 66 for the wheel 51 defining a wheel axis 67 about which the wheel rotates on the spindle 65. The spindle 65 is located either position spaced from the spindle 62 with the axis 65 and 67 parallel.

The hub 63 includes and outer ring 68 surrounding the axis 65 with the outer ring including an inwardly facing gear 69. A pinion 70 is mounted on a shaft 71 extending through the plate 60 and carried thereby on suitable bearings. The shaft 71 is parallel to the axis 65 and drives the pinion in rotation about the axis of the shaft so as to drive the gear 69 in rotation around the axis 65. The shaft 71 is driven by a hydraulic motor 72 carried on a support plate 73 attached to the arm 53 of a position thereon spaced from the plate 60 and inwardly of the spring 54. The plate 73 is based by a triangular base 74.

Rotation of the shaft 71 effected by the hydraulic motor 72 thus causes the pinion to drive the hub 63 around the axis 65 from the first raised position of the spindle 66 as shown in Figure 7 to the second lowered position of the spindle 66 as shown in Figures 5,6 and 8.

In the raised position of the spindle 66 as shown in Figure 7, the spindle is moved to a top center position directly above the axis 65. In this position the wheel 51 is raised relative to the frame. The wheel 51 has a diameter arranged that such that in raised position shown in Figure 7 the frame is substantially at or adjacent ground height so that a load can be moved directly on to the trailer. The spindle 66 tends to center itself over the axis 65 due to the loading of the wheel on the hub 63 which tend to pull the hub upwardly in rotation relative to the plate 60.

When the trailer is loaded, the motor 72 is actuated to drive the shaft 71 causing the pinion the drive the gear in a direction rotating the hub 63 from the 12 o'clock position illustrated in dotted line at 66A in Figure 6 to the 6.30 position shown in full line in Figure 6. Thus the spindle 66 in the lowered position goes just beyond the bottom centered position that is slightly over-center until the hub 63 engages against a stop 75 carried on the plate 60. Thus the hub 63 includes a lobe 76 projecting outwardly to one side of the ring 68 with the lobe defining a side wall 77 which engages against the stop 75. The stop forms a surface which is oriented to engage the surface 77 when the lobe moves to the required position holding the spindle 66 at the 6.30 position.

In addition the stop 75 includes an end plate portion 78 projecting beyond a front face 79 of the hub 63. The end plate portion 78 defines a lip which is in sliding contact with the front face 79 so as to hold that front face against movement away from the plate 60. The lip 78 thus takes loading from the spindle 62 and insures that excessive loading on the spindle 65 tending to twist the bottom of the hub away from the plates 60 is resisted by the inter-engagement between the lip 78 and the surface 79.

The trailer therefore the present invention allows the frame of the trailer to be lowered to the ground for loading and the frame of the trailer to be lifted for transport.

The lifting action is effected using hydraulic action without operator involvement in latching or unlatch elements.

In addition the trailer can be adjusted in length to accommodate different loads with the whole of the frame including the adjustable rear portion being movable in the vertical direction for the loading action.

Turning now to Figures 9,10 and 11 there is shown a fender for the trailer as shown and described above. During upward movement of the wheel for the lowering of the trailer frame to the ground, it is necessary for the fender to accommodate this upward movement. The normal position of the fender just above the wheel during transport movement of the trailer is necessary to prevent release of water, mud and other materials from the road and therefore in the normal position of the trailer, the fender is closely adjacent the wheel. When the wheel is raised, however, the fender must accommodate this movement.

One technique for accommodating movement is shown in Figures 9,10 and 11 wherein there is provided a fender 80 forming two parts 81 and 82. The fender is mounted on the frame member 46 and projects outwardly therefrom over the wheel 83.

Each fender piece 81,82 is mounted on a respective one of a pair of pins 84 and 85 mounted on a projecting outwardly from the frame member 46. Thus each fender piece 81,82 includes a sleeve 86 surrounding the respective pin which is attached to the fender portion by any suitable technique such as welding. The sleeve 86 is arranged at the forward end of the portion 81 and at the rearward end of the portion 82. The sleeve can thus rotate around the pin allowing the fender portion to raise and lower as required. A spring 87 biases the fender portion into the lowered position.

The fender portion 81 is the forward portion and extends from the sleeve 86 on the pin 84 to a rearward edge 88 which is chamfered as indicated in Figure 10.

The rearward portion 82 has a forward chamfered end 89 which matches the chamfered end 88 so that the end 88 rests over the end 89. The sleeve 86 of the portion 82 is arranged at the rearward end and behind the sleeve is provided a downwardly depending mud flap 90. Each portion carries a roller 91,92 which contacts the peripheral surface of the wheel as the wheel is raised upwardly so as to push the portions upwardly as the wheel is raised. The roller is carried on a pin 93 projecting inwardly from an outer flange 94 of the fender.

The fender portions can be locked in place by a pair of locking members 94 and 95 mounted on one edge of the fender, which can be the inside edge, the outside edge or both edges, at the chamfered edges 88 and 89. The locking member 94 comprises an upper cap portion carrying a depending pin 96. The lower locking member 95 comprises a sleeve having an internal bore 97 into which the pin 96 seats. Thus locking members are held together during normal operation so that the fender remains as a single unit until the pin 96 is pulled at the time of raising the wheels to allow the fender portions to be pushed upwardly as shown in Figure 10.

An alternative arrangement is shown in Figure 12 where the side frame member 101 carries the fender generally indicated at 102 formed by two fender portions 103 and 104 substantially as previously described. In this embodiment the frame member 101 includes an extension portion 105 which slides inside the tubular frame member 101 so as to allow the frame member to extend. In this embodiment the front portion 103 is mounted on a sleeve and pin arrangement 107 as previously described.

In this embodiment the rear portion 104 is mounted on a similar sleeve and pin arrangement as indicated at 108. The sleeve and pin 107 is mounted on the frame members 101. The sleeve and pin 108 is mounted on the frame member 105 and is therefore movable rearwardly as the frame is extended by pulling out the extension portion 105. The sleeve and pin arrangement 108 therefore moves from an initial position as shown at 109 in the normal operating position of the fender to an extended position as shown at 108. In this embodiment, therefore, instead of the rear portion pivoting upwardly on the spring, the rear portion remains at a fixed height but is instead moved horizontally away from the position of the wheel 110 allowing the wheel to move upwardly and providing a pushing action only on the forward portion 103.

The fender can also be designed for use with a dual axle arrangement in which the length of one or both portions is increased to accommodate the length of the wheels on the dual axle.

While this application refers to and is primarily concerned with a trailer construction, the same principles can be applied to any wheeled vehicle where a wheel supports a frame and allows the frame to be raised and lowered for loading.